1. Field of the Invention
The present invention relates to a recording apparatus and its record data processing method. More particularly, this invention is concerned with a recording apparatus and its record data processing method in which recording is carried out according to record data such as images or text transferred from a host computer.
2. Description of the Related Art
Various types of serial recording apparatuses in which recording is carried out according to record data transferred from a host computer have widely prevailed in the past. Above all, a dot-matrix recording apparatus is an apparatus for forming a desired record image on a recording material or recording sheet by alternately performing shift in main scan directions of a carriage having a recording head capable of performing dot recording and sheet feed in sub-scan directions, which are orthogonal to the main scan directions, of the recording sheet. Since high-density and relatively high-speed recording can be achieved at low cost, the dot-matrix recording apparatus has been widely adopted in various fields.
In such a serial recording apparatus, when a given number of recording elements (ink-jet ports or electrothermal converting elements forming ink-jet elements in the case of an ink-jet recording apparatus) (equivalent to, for example, 64 dots) are set in array in the sub-scan direction in the recording head, irregularity may occur in recording concentration because of a manufacturing error of each recording element with respect to the other recording elements.
For suppressing such irregular concentration, the following sequence has been repeated in the past: for example, alternate ones of the recording elements set in the array are used for dot recording during a first main scan; sheet feed is performed by a magnitude that is nearly a half of that of a previous sheet feed; and then remaining dot recording is carried out using unused recording elements.
However, according to the foregoing prior art, on the assumption that the whole dot recording is accomplished during one main scan as it previously is, record data is sent from a host computer to a recording apparatus. Nevertheless, the recording apparatus holds the record data so that a record of an intended dot density can be obtained by performing a plurality of main scans, for example, in the foregoing example, by performing two main scans. During each round of main scan, record data is transferred for dot locations at which no dot will be recorded. In the case of a recording apparatus requested to provide especially high resolution, an amount of data becomes duly larger. It is therefore requested to transfer record data at a high speed.
Moreover, the recording apparatus to which record data is transferred needs a print buffer for storing the record data. The necessity of a large-capacity print buffer becomes one factor of an increase in cost.